Danny Wilson says Saturday's win at Carlisle United was tempered by a serious looking injury to Kevin McDonald.
McDonald was on the end of a couple heavy challenges in the first half at Brunton Park and subsequently limped off early in the second period.
On his midfielder's health, Wilson remarked: "Kev was on the end of a really nasty challenge. He strapped it up for the second half but it was soon obvious he couldn't continue.
"We don't know how bad it is because of the swelling. We will access him in due course, but looking at the state of his ankle it doesn't look too clever.
"It was a very late and high tackle and it is frustrating that challenge is punished the same way as a shirt pull."
Looking ahead to Saturday's top of the table clash against Tranmere Rovers at Bramall Lane, Wilson concluded:
"It promises to be a good game, Tranmere are at the top on merit.
"We needed to come to Carlisle and produce a dominant display and we did that, especially in the first half, and now everything is focused on Saturday's home game."